Network sharing is a concept introduced to allow operators to share a Radio Access Network (RAN) node (i.e. RAN sharing). With the popularization of Long Term Evolution (LTE), it has become necessary for the operators who removed the 2G/3G infrastructures to share the RAN node (or cell under control of a base station) on account of the legacy 2G/3G terminal users. The base station supporting the network sharing may broadcast a Public Land Mobile Network Identifier (PLMN ID) of the operators sharing the base station.
FIG. 1 is a schematic diagram illustrating a network sharing concept according to a conventional technology.
Referring to FIG. 1, there may be supporting User Equipment (UE) having PLMN selection function capable of selecting one of PLMN IDs broadcast by 2G/3G network and non-supporting UE having no PLMN selection function in the network sharing mode. In this case, in order to assist the non-supporting UE to operate normally in the network sharing mode, the base stations (or the cells under the control of the base stations) 120 and 125 may broadcast a common PLMN ID 130 and 135 determined through negotiation among the operators 111, 113, and 115. If the base stations 120 and 125 broadcast the common PLMN ID 130 and 135, the other PLMN IDs which are called additional PLMN IDs 141, 143, and 145 can be used only by the supporting UEs.